The present invention relates to unidirectionally valved drip chamber, inlet port assemblies, particularly those useful for liquid collection containers such as urinary collection bags.
The use of disposable, flexible collection containers for surgical and other applications has increased the potential for refluxion of the collected liquid back into the drainage line. In addition to inversion of the container, which can occur during transportation of the patient to and from surgery, internal or external pressures of various origins can cause the container to distort and hydrodynamically reflux the liquid. Where the flexible container is a urinary collection bag, refluxion of the collected urine can severely distend the patient's bladder thereby causing trauma and introducing bacterial infection to the bladder.
Several prior art devices have been designed to prevent the refluxion of collected liquids by the employment of a unidirectional valve. U.S. Pat. No. 3,529,599 granted to Folkman, et al. on Sept. 22, 1970 discloses a collection container for medical liquids having a disc valve. U.S. Pat. No. 3,583,401 granted to Valliancourt et al. on June 8, 1971 discloses a vented closed drainage system having a flutter valve. U.S. Pat. No. 3,626,980 granted to Svensson on Dec. 14, 1971 discloses a bacteria barrier device employing a lift valve. U.S. Pat. No. 3,901,235 granted to Patel, et al. discloses an antireflux device for urinary collection bags comprising a flap valve.